Summary auto-generated
Researchers isolated a novel spiral-shaped bacterium from laboratory mice intestines and designated it Helicobacter rodentium sp. nov. The organism is urease-negative, a unique characteristic among murine Helicobacter species, and possesses single, nonsheathed bipolar flagella, a feature shared only with Helicobacter pullorum. The bacteria grow under microaerobic and anaerobic conditions at 37°C and 42°C but not at 25°C. Biochemical analysis revealed the organism is weakly catalase and oxidase positive, reduces nitrate to nitrite, and is resistant to cephalothin and nalidixic acid. Genetic analysis using 16S rRNA sequencing confirmed H. rodentium is a distinct species separate from known Helicobacter spp., clustering with other murine helicobacters and Flexispira rappini. While typically found in asymptomatic mice as part of normal intestinal flora, the organism was also recovered from immunocompromised scid mice with diarrhea co-infected with Helicobacter bilis. The type strain MIT 95-1707 has been deposited in culture collections, and species-specific PCR primers were developed for identification.
Key findings
- H. rodentium is the first urease-negative Helicobacter species isolated from mouse intestines, distinguishing it from previously described murine helicobacters
- The organism possesses unique nonsheathed bipolar flagella (shared only with H. pullorum among Helicobacter species) and exhibits specific biochemical characteristics including nitrate reduction and antibiotic resistance patterns
- 16S rRNA gene sequencing and phylogenetic analysis confirm H. rodentium represents a novel species distinct from known Helicobacter and related genera
- Species-specific PCR primers were developed for reliable identification, producing a 166-bp product unique to H. rodentium strains
This summary was generated automatically from the article PDF and is not part of the original publication. Refer to the PDF for the authoritative text.
Abstract
A spiral-shaped bacterium with bipolar, single, nonsheathed flagella was isolated from the intestines of laboratory mice. The organism grew at 37 and 42°C under microaerobic and anaerobic conditions, did not hydrolyze urea, was weakly positive for catalase and oxidase, reduced nitrate to nitrite, did not hydrolyze indoxyl acetate or hippurate, and was resistant to cephalothin and nalidixic acid. This is the first ureasenegative, murine Helicobacter spp. isolated from intestines. Also, Helicobacter pullorum and this bacterium are unique among the genus Helicobacter in having nonsheathed flagella. The new bacterium appears to be part of the normal intestinal flora; although its pathogenic potential is unknown, this organism was also isolated from scid mice with diarrhea that were co-infected with Helicobacter bilis. On the basis of 16S rRNA gene sequence analysis data and biochemical and phenotypic criteria, the new organism is classified as a novel helicobacter, for which we propose the name Helicobacter rodentium. The type strain is MIT 95-1707 (= ATCC 700285).